A damaging effect of manganese on fabrics during bleaching has been known since the 19th century. In the 1960's and '70's, efforts were made to include simple Mn(II) salts in detergents, but none saw commercial success. More recently, metal-containing catalysts containing macrocyclic ligands have been described for use in bleaching compositions. Such catalysts include those described as manganese-containing derivatives of small macrocycles, especially 1,4,7-trimethyl-1,4,7-triazacyclononane. These catalysts assertedly catalyze the bleaching action of peroxy compounds against various stains. Several are said to be effective in washing and bleaching of substrates, including in laundry and cleaning applications and in the textile, paper and wood pulp industries. However, such metal-containing bleach catalysts, especially these manganese-containing catalysts, still have shortcomings, for example a tendency to damage textile fabric, relatively high cost, high color, and the ability to locally stain or discolor substrates.
Salts of cationic-metal dry cave complexes have been described in U.S. Pat. No. 4,888,032, to Busch, Dec. 19, 1989 as complexing oxygen reversibly, and are taught as being useful for oxygen scavenging and separating oxygen from air. A wide variety of ligands are taught to be usable, some of which include macrocycle ring structures and bridging groups. See also: D. H. Busch, Chemical Reviews, (1993), 93, 847-880, for example the discussion of superstructures on polydentate ligands at pages 856-857, and references cited therein, as well as B. K. Coltrain et al., “Oxygen Activation by Transition Metal Complexes of Macrobicyclic Cyclidene Ligands” in “The Activation of Dioxygen and Homogeneous Catalytic Oxidation”, Ed. by E. H. R. Barton, et al. (Plenum Press, NY; 1993), pp. 359-380.
More recently the literature on azamacrocycles has grown at a rapid pace. Among the many references are Hancock et. al., J. Chem. Soc., Chem. Commun., (1987), 1129-1130; Weisman et al., “Synthesis and Transition Metal Complexes of New Cross-Bridged Tetraamine Ligands”, Chem. Commun., (1996), 947-948; U.S. Pat. No. 5,428,180, U.S. Pat. No. 5,504,075, and U.S. Pat. No. 5,126,464, all to Burrows et al.; U.S. Pat. No. 5,480,990, to Kiefer et al.; and U.S. Pat. No. 5,374,416, to Rousseaux et al.
Homogeneous transition metal catalysis is a broad realm that has enjoyed intensive activity leading to a number of large scale chemical processes; e.g., the Monsanto acetic acid process, the Dupont adiponitrile process, and others, among which certain famous ones involve oxidations (Wacker Process, Midcentury Process). Further, transition metal oxidation catalysis has been promoted heavily in studies on the biomimicry of the monooxygenase enzymes, especially cytochrome P450. Whereas such studies have emphasized and shown the prowess of the native porphyrin prosthetic group, others have shown that certain oxidative capabilities exist in the same metal ions in the simple solvated condition. This history reveals the possibility that catalytic oxidation may alter almost all families of organic compounds to yield valuable products, but successful applications depend on the activity of the putative catalyst, it survivability under reaction conditions, its selectivity, and the absence of undesirable side reactions or over-reaction.
It has now surprisingly been determined that the use of certain transition-metal catalysts of specific rigid macropolycycles, preferably containing cross-bridging, have exceptional kinetic stability such that the metal ions only dissociate very slowly under conditions which would destroy complexes with ordinary ligands, and further have exceptional thermal stability. Thus, the present invention catalyst systems can provide one or more important benefits. These include improved effectiveness and in some instances even synergy with one or more primary oxidants such as hydrogen peroxide, hydrophilically or hydrophobically activated hydrogen peroxide, preformed peracids, monopersulfate or hypochlorite; the ability to be effective catalysts, some, especially those containing Mn(II), having little to no color and allowing great formulation flexibility for use in consumer products where product aesthetics are very important; and effectiveness on a variety of substrates and reactants, including a variety of soiled or stained fabrics or hard surfaces while minimizing tendency to stain or damage such surfaces.
Therefore, the present invention provides improved catalytic systems containing transition-metal oxidation catalysts, and methods which utilize these catalysts and catalytic systems in the area of chemical syntheses involving organic oxidation reactions, such as oxidation of organic functional groups, hydrocarbons, or heteroatoms, and epoxidation of alkenes; oxidation of oxidizable stains on fabrics and hard surfaces; oxidation of reactants in solutions; pulp and paper bleaching; the oxidation of organic pollutants and for other equivalent highly desirable purposes.
These and other objects are secured herein, as will be seen from the following disclosures.